PAINTING ALUMINUM: advice needed

[halps]

G'Day Bearers of great knowledge,

HISTORY: Today I had a look at a great caravan outside of Brisbane. It was a one owner, no leaks, 16f or so. Very well maintained...a real credit to it's current owner. It is 3 or so feet larger than our current van and with 3 kids it is certainly an attractive purchase.

CONTEXT: I have no experience painting aluminum. There are some areas that have what I would call "normal wear and tear" that require painting. There are also a number of small star-burst "crazing" less than the size of a 5c piece. I didn't have my camera. (I wish I did). The current owner has painted the "flash" on the side with a brush...I would prefer a more "professional" finish.

QUESTIONS: If I was to paint the aluminum do I have to strip the whole van back to bare metal? Or simply patch sand the poor areas, prime/undercoat the whole van and then a couple of finishing coats?

Any advice will be graciously received.
Warm Regards,
HALPS

[seeshell]

Hi Halps

Certainly something that happens around here alot - there's probably advice on paint you can search for in the Technical section of the website, as I'm sure others have probably had the same questions!

There's a lot of good advice for painting houses with aluminium siding - and it would have to be somewhat similar you'd think. Experts will be able to point out the differences from their own experiences with their vans no doubt.

This website had a few good bits of advice: www.askthebuilder.com/122_How_to_Paint_Aluminum_Siding.shtml

Seemed to focus on a few things like good prep, good paint, but they didn't say you have to remove all the paint just whatever would come loose with a good stiff handwash (power washing to be avoided per article) but I think this is where house painting and van painting might depart - you'd want a more polished look.

Perhaps the star crazing would require a light sand so it didn't show through as might also be the case where there was heavy paint cracking - your idea there sounds very reasonable.

If you're going to paint the whole van perhaps a small spray kit would be the go (rent, borrow or buy a compressor)? You could paint the base coats and then mask off a new stripe with paper and tape and spray it on which would give a more professional and sharp finish.

Or you could make use of LarryLarrikin1's new Caravan Spray Shop if you are within a close enough radius. He's reasonably priced.

Good luck with your project whatever you decide

Seeshell

[Roehm3108]

The very first van I ever restored was a baby Franklin (yep Franklin1 I was a Franklin tragic - way before this forum started. But I got smart ;D ;D ;D). Went and spoke to a paint guy who knew his onions quite well, and his response was simple - use a good quality exterior house paint!

Prepping is important, like a good sand with the flaking/starring parts and a good wash down with sugar soap. Make sure you get as much of that powdery stuff off, so that the paint can bind onto the aluminium. Exterior house paint is self-priming, so no primer is necessary. Being acrylic, it also flexes well with the heat expansion/contraction of the aluminium.

As seashell said, you can use a spraygun. I used a short nape roller, which gave a slightly stippled finish, which I liked as it hid any stone dints to some extent. The end result was good and it lasted a good number of years, before I sold that van.

It really depends on your budget too. I suppose you could use two-pac, but that's pretty dear. But for a neat, clean job which will last the duration of the paint warranty, my choice is the exterior house paint.

OR, if your pockets are REALLY deep, you could take it to larrythelarrikin!!!! Just kidding Larry ;D ;D

Ray

[barbarab]

Hi seashell,
I'm not sure I like the advice on the website you recommended. They are suggesting you use an oil based primer, then an acrylic over the top.
As far as I know, you never use acrylic over oil as it will crack. It's fine the other way around - you can use oil over acrylic, but not what he's suggesting.
Barbara B

[halps]

Thanks guys and dolls,
Keep the comments/advice coming as it is improving my confidence in perhaps tackling the job myself. ;D

I have read in some depth the robust discussion in other threads about oil vs acrylic paints. It makes for interesting reading for someone like me that does not come from a trade/hotrod/resto background.

I really appreciate the effort that you have gone to in replying to my request. Thanks so much Seeshell, Ray & Barbara B.

Any other advice will be eagerly read...6 or 7 times...


Warm Regards,
HALPS

It will be a sad day in the Halpsie household if I buy this van as the Capricorn will have to go on the market.

[seeshell]

Hi Barbarab

You're absolutely right about painting acrylic directly onto oil paint - it will scratch right off with the slightest touch. To make it work properly, you must install a special primer coat first between the oil and acrylic. The painting sequence is the following:

oil primer paint --> intermediate primer coat --> acrylic paint

You could ask your local paint supplier which is the best primer for your application - there are primers that stick to anything, including glass, so there will be one for any application. The subsequent acrylic coats will stick to the intermediate primer like the proverbial and your finished result will be great.

From the article they were not recommending a full acrylic treatment (including acrylic primer) because of some of the components in the acrylic primer paint don't hold up quite as well (inclusions like ammonia that damage aluminium). So hence the special advice about oil based primer and the extra steps noted.

Cheers
Seeshell